Fuel composition and method of manufacture



Patented Oct. 2, 1934 UNITED STATES FUEL COMPOSITION AND METHOD OF MANUFACTURE Lester F. Hoyt, East Aurora, and William Alvah Smith, Hamburg, N. Y.; said Hoyt assignor to Said Smith No Drawing. Application'May 23, 1931, Serial No. 539,634

8 Claims.

This invention relates to a motor fuel composition and process of manufacturing motor fuels, particularly those substantially free of gum and color-stable. The gasolines produced by modern cracking processes even though carefully refined by treatment with sulphuric acid and other refining agents develop a yellow color and deposit gums. Off-color gasolines of this character must be either retreated or sold at substantial loss in Furthermore the use of motor fuel containing gummy resinous material causes deposition of the gum in the fuel supply line on the parts of the carbureter and on the valves of the engine,

thus causing clogging and sticking of the valves with a consequent reduction in emciency of operation of the motor. I

An object of the present invention is to provide a process for the treatment of petroleum distillates subject to the defects described above in which the distillate is treated to inhibit the formation of gums and prevent the distillate from going off color.

In accordance with this object the invention comprises the steps of forming a composition motor fuel by adding to the gasoline or distillate to be treated a chemical gum-inhibiting agent adapted to render the distillate gum-stable and a chemical bleaching or color-stabilizing agent adapted to prevent the discoloration of the gasoline due to standing or to the action of sunlight.

A further object of the invention is the production of a motor fuel composition which is substantially gum-free and color-stable and which will remain such under ordinary storage and transportation conditions.

In accordance with these objects the improved motor fuel composition comprises a mixture which includes a hydrocarbon oil distillate, quinhydrone and a gum inhibitor selected from a group of compounds consisting of the derivatives of benzene having an NHz group replacing a hydrogen of the benzene ring in which in addition there is either a COOH or NHz group replacing another hydrogen of the same benzene ring. If

the distillate is already color stable, the quinhydrone may be omitted from the mixture.

In carrying out the improved process of the present invention in its preferred form, the gasoline or pressure distillate is subjected to a preliminary treatment principally to remove hydrogen sulfide, carbon bisulphide and elemental sulphur. To accomplish this the pressure distillate or gasoline either in vapor or liquid phase is preferably passed in intimate contact with granular caustic which reacts with the sulphur constituents mentioned above. The distillate is then passed in intimate contact with granular copper silicate or may be sweetened with sodium plumbite solution or other sweetening agent. To the sweetened pretreated distillate is finally added a small proportion'of the color stabilizer quinhydrone, and in addition a small proportion of one or more of the gum inhibiting agents of the class defined above. The distillate motor fuel treated in this manner will remain color-and-gumstable for substantial periods of time, and will not depreciate materially in anti-knock value.

The color-stabilizer quinh-ydrone is in fact a powerful bleaching agent for ofi-color distillates, and may be added to the distillate at any time and for the sole purpose of improving its color. Quinhydrone furthermore does not accelerate gum formation in the distillate, but is in fact a mild gum-inhibiting agent.

For the purpose of securing rapid solution of the quinhydrone or the gum inhibiting agent in the distillate either or both may be first dissolved in a carrier liquid or intermediate solvent. The resulting solution or solutions of the agents may be mixed with the gasoline or other distillate as described above.

Examples of the benzene derivatives used as gum inhibitors in connection with the present invention are the following: o-amino benzoic acid (antharnilic acid), m-amino benzoic acid, p-amino benzoic acid, o-phenylenediamine, mphenylenediamine, p-phenylenediamine.

Repeated tests have shown that if substitutions are made in the NH2 or COOH groups of the above class, the resulting compounds have markedly less gum inhibiting action. The tests also indicate that in compounds in which the position of the NH2 with respect to the COOH or NHz is ortho, the inhibiting action is usually best; para, 95 next best and meta least efiective of the three positions.

The type or character of the gasoline to be treated has some efiect upon the usefulness and quantity of the chemical gum inhibitor to be employed. For example some highly unsaturated distillates, which without an inhibitor; depreciate rapidly and form substantial amounts of gum with a consequent reduction in anti-knock value, require larger proportions of inhibitors than other gasolines. The use of the gum inhibiting agents and colon-stabilizing agent according to the process of the present invention has shown that gasolines from different sources and which have been refined by different refining methods require 110 varying proportions of the inhibitors to render them stable. The proportion of gum inhibitor required should in no case exceed 25 pounds per hundred barrels of gasoline and in most cases from five pounds to one tenth pound per hundred barrels is sufiicient. The usual proportion of an inhibitor is about one pound per one hundred barrels of gasoline. The proportion of quinhydrone to gasoline should be in about the proportions mentioned for the gum inhibiting agents,

but the quantity may vary considerablydepencb ing upon the initial color of the gasoline to be treated. While the distillates treated in accordance with the present invention are preferably treated with copper silicate prior to the addition of the inhibitors, nevertheless distillates refined by the usual acid-alkali treatment may be effectively used and benefited by the process of the present invention. In some cases however the gum inhibitor used in the ordinary proportion to distillate (one pound to one hundred barrels) is not as effective as in the case where copper silicate treated distillate is employed. This may be largely overcome by using a somewhat larger proportion of inhibitor to distillate.

The efiectiveness as gum inhibitors of the amino benzene derivatives described in connec- Copper dish gu per 00.)

Sample With inhibitor Blank p'a'mino benzoic acid o-phenylenediammem-phenylcnediannne. p-phenylenediammeo-amino benzoic acid Cracked gasolines which have been treated by the usual sulphuric acid and alkali do not give as good results as the copper silicate treated gasolines, but even in this case there is a substantial improvement from the use of inhibitors. For example, a sulphuric acid treated gasoline stabilized with anthranilic acid gave a 41 mg. gum where the blank was 83.

The efiectiveness of anthranilic acid as a gum inhibitor and of quinhydrone as a colorestabilizing agent is shown by a two months storage test in which the gasoline stored contained .004 grams of anthranilic acid and .001 grams of quinhydrone per 100 cc. The initial gasoline showed a copper dish gum of '7 mg. as compared with a blank of 30 mg. while the inhibited gasoline after storage for two months showed a copper dish gum of only 12 mg. compared with a blank of 48 mg.

The class of gum inhibiting agents disclosed above not only serves to reduce or inhibit formation of gum in gasolines, but permit the use of other treating steps which leave in the gasoline the unsaturated compounds which are largely responsible for the high anti-knock value of the gasoline.

Instead of using a single gum inhibitor, a mixture of one or more of the compounds of the class described may be used.

Having thus described the invention in its preferred form what is claimed as new is:

l. A motor fuel mixture comprising cracked hydrocarbon spirts normally tending to deteriorate in storage and containing an aromatic ring compound substituted with amino and carboxy- -lic acid radicals in quantity suflicient to substantially retard such deterioration.

2. The process of inhibiting the formation of gums in cracked gasolines normally tending to deposit gum which comprises dissolving therein a small proportion of an amino benzoic acid sumcient in quantity to prevent said gum formation.

3. The process of stabilizing a cracked unsaturated gasoline motor fuel normally tending to develop gum-forming constituents to prevent formation of gummy or resinous materials therein which comprises dissolving in the gasoline a small proportion of anthranilic acid in quantity sumcient to substantially prevent said gum formation.

4. The process of inhibiting the formation of gums in cracked gasolines and stabilizing the color thereof which comprises dissolving therein a small proportion of anthranilic acid and quinhydrone in quantities sumcient to respectively inhibit gum formation in the gasoline and to stabilize the color of the gasoline.

5. A motor'fuel mixture comprising a cracked distillate and a small proportion of an amino benzoic acid dissolved therein in quantity sufiicient to prevent formation of gum in said mixture.

6. A motor fuel mixture comprising a cracked petroleum oil distillate and a small proportion of anthranilic acid said anthranilic acid being present in sufiicient quantity to prevent gum formation in said mixture.

7. The process of treating a cracked petroleum distillate normally tending to deposit gum to inhibit the formation of gum therein which comprises. dissolving in the distillate a small proportion of quinhydrone, and a small proportion of an amino benzene derivative sufiicient in quantity to prevent substantial gum formation and in which a second hydrogen of the benzene ring is replaced by a radical selected from the group of radicals consisting of NH2, and COOH.

8. A composition comprising a cracked petroleum oil product,a small proportion of quinhydrone, and asmall proportion of an unsubstituted amino benzene compound in which a second hydrogen of the benzene ring is replaced by a group selected from the radicals consisting of N112 and COOH, said compound being present in sumcient quantity to prevent substantial formation of gum in said composition. 

